I don't think $75 Million was a small budget for the first X-Men film. Of course it sounds small today because some major blockbuster films today have a budget of 200 to 250 million dollars. But back in 2000, the most expensive movie (The Perfect Storm) that was released during that year had a budget of $140 million. The press also expected the movie to flop. So I think a $75million budget is a very reasonable budget for the first X-Men movie.